Problem (One tailed test) A rental agent claims that the mean monthly rent, mu, for apartments on the east side of town is less than $725. A random sample of 13 monthly rents for apartments on the east side has a mean of $724, with a standard deviation of $15. If we assume that the monthly rents for apartments on the east sid
Problem (two tailed test) A manufacturer claims that the mean lifetime, mu, of its light bulbs is 44 months. The standard deviation of these lifetimes is 7 months. Seventy bulbs are selected at random, and their mean lifetime is found to be 43 months. Can we conclude, at the 0.1 level of significance, that the mean lifetime o
Problem (Null Hypothesis) A union of restaurant and foodservice workers would like to estimate this year's mean hourly wage, mu, of foodservice workers in the U.S. Last year's mean hourly wage was $8.16, and there is reason to believe that this year's value is different from last year's. The union decides to do a statistica
The mean SAT score in mathematics is 522. The founders of a nationwide SAT preparation course claim that graduates of the course score higher, on average, than the national mean. Suppose that the founders of the course want to carry out a hypothesis test to see if their claim has merit. State the null hypothesis and the alternat
See attached file for full problem description. Where appropriate, always use an alpha of .05, always use the one tail test, always use a confidence interval of 95%, and assume Z = 1.96 in formulas for confidence interval calculations and sample size calculations. The above table represents a random sample of 16 chemical
A presidential candidate's aide estimates that, among all college students, the proportion p who intend to vote in the upcoming election is at most 65%. If 196 out of a random sample of 270 college students expressed an intent to vote, can the aide's estimate be rejected at the 0.1 level of significance? What is the null hyp
A recent article in the Wall Street Journal reported that the 30-year mortgage rate is now less than 6 percent. A sample of eight small banks in the Midwest revealed the following 30- year rates (in percent): 4.8 5.3 6.5 4.8 6.1 5.8 6.2 5.6 At the .01 significance level, can we conclude that the 30-year mortgage rate for s
The manufacturer of the X-15 steel-belted radial truck tire claims that the mean mileage the tire can be driven before the tread wears out is 60,000 miles. The standard deviation of the mileage is 5,000 miles. The Crosset Truck Company bought 48 tires and found that the mean mileage for their trucks is 59,500 miles. Is Crosset's
Please help with the following problem. Please provide step-by-step calculations for the following problem in both Word and Excel. A machine is set to fill a bottle with 9 grams of medicine. A sample of 8 recently filled bottles revealed the following grams of medicine: 9.2, 8.7, 8.9, 8.4, 8.3, 8.5. Using a One Sample t T
The mean length of stay of employees for a company in a particular dangerous industry is 16.7 months. One hundred randomly selected employees from a less dangerous industry had a mean length of stay of 17.8 months. At the 0.05 significance level, do the data provide sufficient evidence to conclude the mean length of stay of e
Stress levels of three different classes of physics students were measured on a scale of 1 to 20, with 20 being the greatest level of stress. At a 0.05 significance level, are the stress levels equal among all remaining students at the end of week 5 in all three classes? Class #1 Class #2 Class #3 9 13 10 7 20
It is commonly accepted that the mean temperature of humans is 98.6oF. The CEO of Au & Associates has nothing better to do but measured the temperatures of 26 department managers 1 to 4 times daily to get a total of 123 measurements. The collected data yielded a sample mean of 98.4oF and a sample standard deviation of 0.7oF.
A sample of 120 observations revealed that p = .30. At the 0.05 significance level, can the null hypothesis be rejected? a) state the decision rule b)compute the value of the test statistic c)what is your decision regarding the null hypothesis?
Using AIU's large database of survey responses from the AIU data set, complete the following: Perform hypothesis testing on one variable's data. (Choose either the intrinsic or extrinsic column.) Perform a t-test by formulating a null and an alternative statement, choosing an acceptable significance value, selecting the test
Safegate Foods, Inc., is redesigning the checkout lanes in its supermarkets throughout the country and is considering two designs. Tests on customer checkout times conducted at two stores where the new systems have been installed result in the following summary of the data. (see attached SafeGate file) Test at the .05 level o
A random sample of 15 observations provided x-bar = 182 and s = 12. (a) Test H0: μ = 190 versus H1: μ < 190 at α = .05. State your assumption about the population distribution. (b) What can you say about the P-value of the test statistic calculated in part (a)? A weight loss program advertises "LOSE 40 P
Environmental health indicators include air quality, water quality, and food quality. Twenty-five years ago, 47% of U.S. food samples contained pesticide residues. In a recent study, 44 of 125 food samples contained pesticide residues. a. State the hypotheses that can be used to show that the population proportion declined.
Need help setting up, understanding and solving this problem: At Western University the historical mean of scholarship examination scores for freshman applications is 900. A historical population standard deviation σ = 180 is assumed known. Each year, the assistant dean uses a sample of applications to determine whether
A sample of 500 respondents was selected in a large metropolitan area in order to determine information concerning consumer behavior. Among the questions asked was "Do you enjoy shopping for clothing?" Of the 240 males, 136 answered "Yes". Of the 260 females, 224 answered "Yes". 5.1 Is there evidence of a difference in th
1. Does using statistics as the sole basis for making a decision eliminate the need for ethical considerations? Why or why not? What role do ethics play when performing statistical testing?
Need help setting up, solving and understanding this problem: During the 2004 election year, new polling results were reported daily. In an IBD/TIPP poll of 910 adults, 503 respondents reported that they were optimistic about the national outlook, and The President's leadership index jumped 4.7 points to 55.3. a. What is
The cost of a one-carat VS2 clarity, H color diamond from Diamond Source USA is $5600. A Midwestern jeweler makes calls to contacts in the diamond district of New York City to see whether the mean price of diamonds there differs from $5600. a. Formulate hypotheses that can be used to determine whether the mean price in New Yo
Problem #1 Independent random samples of 36 and 50 observations are drawn from two quantitative populations, 1 and 2, respectively. The sample data summary is shown here: Sample 1 Sample 2 Sample Size 36 50 Sample Mean 1.28 1.35 Sample Variance 0.058 0.056 Do the data prese
See the attached file. Problem #1 A total of 200 people in each of three grocery stores were asked if they favored, opposed, or were indifferent to the sale of lottery tickets in grocery stores. The results of the survey are summarized below. Test the hypothesis at α= 0.05. Opinion Store A Store B Store C Favo
Two boats, the Prada (Italy) and the Oracle (U.S.A.), are competing for a spot in the upcoming America's Cup race. They race over a part of the course several times. Below are the sample times in minutes. At the .05 significance level, can we conclude that there is a difference in their mean times? Boat
Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the afternoon shift than on the day shift. A sample of 54 day shift workers showed that the mean number of units produced was 345, with a standard deviation of 21. A sample of 60 afternoon-shift workers sh
The management of White Industries is considering a new method of assembling its golf cart. The present method requires 42.3 minutes, on average, to assemble a cart. The mean assembly time for a random sample of 24 carts, using the new method, was 40.6 minutes, and the standard deviation of the sample was 2.7 minutes. Using the
The MacBurger restaurant chain claims that the waiting time of customers for service is normally distributed, with a mean of 3 minutes and a standard deviation of 1 minute. The quality-assurance department found in a sample of 50 customers at the Warren Road MacBurger that the mean waiting time was 2.75 minutes. At the .05 level
The historical reports from two major networks showed that the mean number of commercials aired during prime time was equal for both networks last year. In order to find out whether they still air the same number of commercials on average or not, random and independent samples of 85 recent prime time airings from both networks
An automobile assembly line operation has a scheduled mean completion time, mean, of 14.7 minutes. The standard deviation of completion times is 1.2 minutes. It is claimed that, under new management, the mean completion time has decreased. To test this claim, a random sample of 60 completion times under new management was taken.